Electric cars are far from silent, Which? reveals10 noisiest cars tested includes electrics cars

26 September 2012

Which? Car has revealed the 10 noisiest cars on sale. And contrary to received wisdom on the subject, electric cars are among the most noisy of all.

The Mitsubishi i-MiEV and Peugeot iOn, which are pure electric cars, both feature in the list due to very high recorded decibel levels in the cabin at motorway speeds.

Also in the 'bottom 10' list is the new Mini Roadster, which slots in as the fourth noisiest car tested by Which? 

Convertibles are worst

The noisiest currently-available car we tested is the Mazda MX-5 Roadster-Coupe 2.0. Our noise meter measured a deafening 76.6 decibels (dB) in the cabin on the motorway. 

In fact, three of the four noisiest cars tested are convertibles. The Fiat 500C TwinAir was almost as noisy as the Mazda MX-5, measuring 76.4dB, while the new Mini Roadster measured a boomy 75.3dB. 

Of the Mini Roadster, Which? testers said: 'Don't buy a Roadster if you like relaxed open-topped cruising. The problem is wind noise: it's all too audible in the cabin because of the Roadster's poorly insulated fabric top. The Cooper S's petrol engine is rather raucous at high revs too.'

Electric cars are far from silent

It's perhaps not surprising that poorly insulated convertibles should be noisy, but two electric cars also make the list. 

The Mitsubishi i-MiEV and Peugeot iOn both measured 74.1dB on the motorway, making them the equal eighth noisiest cars tested by Which?  

In our Peugeot iOn review, Which? Car testers said: 'Wind noise is all you hear up to about 50mph. As this increases the faster you travel, it does somewhat negate the advantages of the quiet electric motor - at motorway speeds it's really quite loud.'

The 10 noisiest cars tested by Which?

Mazda MX-5 Roadster-Coupe 2.0 - 76.6dB
Fiat 500C 0.9 TwinAir - 76.4dB
Hyundai i10 1.2 - 75.6dB
Mini Cooper S Roadster - 75.3dB
Renault Twingo 1.2 - 74.9dB
Ford Ka 1.2 - 74.3dB
Nissan 370Z Coupe - 74.3dB
Mitsubishi i-MiEV/Peugeot iOn - 74.1dB
Peugeot 107 - 74.0dB 
Smart ForTwo 1.0 - 73.9dB

* Table includes only cars that are currently on sale new

How we measure cabin noise

To make sure we have the most realistic measurement of interior noise, we use a sound level meter to measure the dB level inside the cabin centre at motorway speeds with a half load and standard summer tyres. We take the measurement travelling in both directions on the motorway and calculate the average figure.

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